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UNITED STATES PATENT OFFICE
LIQUID CUTOFF DEVICE
David N. Fulton, Bernardsville, N. J.
Application February 18, 1941, Serial No. 379,520
5 Claims. (CI. 226—127)
The; present invention relates to improvements, in liquid cut-off devices and. has for an object to provide an automatic cut-off. fox: liquids: being delivered through conduits, for instance as a hose attached to a dispensing pump for gasoline used in connection with service stations for replenishing the, tanks of automobiles.
A further object; of the invention is to, provide, in association with such: conduit, and the. valve nozzle usually carried thereby and inserted in the neck of the automobile gas. tank, a device, automatic in action to suspend delivery of the gasoline or other liquid through said conduit and nozzle whenever the liquid in the automobile tank, ox other receptacle;, wells up or rises in a. regurgitant: manner; to a point: that, unless arrested, would result, in the overflow of the liquid from the tank..
The. attendants at. these service, stations are notoriously careless and it is a rather common sight to see the gas tanks of automobiles overflowing in the act of being filled with fuel.. This condition occurs not only when the attendants inadvertently allow a filled tank to overflow, but such tanks become air bound and for other reasons, before they become filled, create a condition where the liquid will momentarily, but quickly, rise in the filling neck and overflow before even a careful operator can close the valve on the nozzle and shut off the further supply of the liquid. The gasoline or other liquid which is everywhere observed to be, splashing out of automobile gas tanks and other containers; is: a source of expense and danger.. A purpose of the present invention is to avoid both such conditions.
A still further object of the invention resides in accomplishing the above objects in an extremely simple manner, by an economical construction, of a character to. he approved by the underwriters,, and which will in nowise change the appearance of the; dispensing, hose or nozzle nor interfere in any way with, the manipulations of the hose and nozzle in. the usual: expeditious manner by the attendant, and which will not interfere with his free and unimpeded operation of the nozzle valve.,
With the foregoing and other objects in view,, which will be apparent to those skilled in this art, the invention will be more fully explained hereinafter and particularly pointed out in the, subjoined claims.
In the drawing,, in which identical or similar parts are denoted by the same reference characters throughout the several views.
Figure 1 is. a. diagrammatic view of an improved
automatic cut-off device constructed in accordance with the, present invention.
Figure 2 is. a top plan fragmentary view of a conventional form of gasoline dispensing nozzle equipped with the improved device.
Figure 3 is a fragmentary side elevation of the same, and
Figure 4 is an end view of such nozzle showing the mouth of the air tube.
Referring more particularly to the drawing 10 designates a conduit for fluid of any suitable character, for instance, such a conduit as is to be found in the pumps erected in gasoline service stations: to which a flexible hose 1 1 is attached for convenience in directing the nozzle 12 carried by the free end of the hose 13 to a suitable point for entering the filling neck of the gasoline tank of an automobile or such other receptacle to which it is desired to deliver fluid from such conduit. The nozzle 12 is conventionally metallic and equipped with a. trigger operated valve which may be released by the attendant at the service station when the nozzle. 12 is inserted in the filling neck of the tank.
In accordance with the invention I place in the conduit ID at a point remote from the nozzle. 12 and preferably concealed in the casing of the pump structure a normally open valve 13 held yieldably open as by a spring 14 or other instrumentality and closable against seat 15. formed in a diaphragm 16 of the valve casing VI which is included in the conduit I S.
The valye stem 18 constitutes the core of a solenoid 19 included in the circuit 20, 21 normally open at the contacts 22 and 23. and closable by a liquid electrolyte 24 in a substantially Utube 25. The liquid 24 may he mercury but is preferably some acidulous iiquid performing the functions of an electric conductor and yet nonfreezable at, out-door temperatures encountered where gasoline pumps are usually placed, and which is also inexpensive and easily procurable.
The circuit 20, 21 may be fed from the usual power mains or from any other source of D. C. or A, C, supply. Usually the transformer indicated will be necessary to step down the outside current to the circuit 2.0, 21. There is also shown a bell signal tapped off the secondary of the transformer which may or may not be used, but which, would be desirable or of advantage to the attendant.
One; leg of the U-tube may be open at 26 to permit the electrolyte to breathe freely so as not to imp.ede the facility of its flow in making and breaking, contact with the upper contact 22, it
being understood that this upper contact 22 is above the normal liquid level of the U-tube 25 to the end that the circuit 20, 21 is normally open.
The other leg of the U-tube is connected to an air tube 27, which, in effect, is a continuation of the U-tube 25. Such air tube extends down along the flexible hose 11 or within the hose and it preferably enters the hose at one point or the nozzle in order not to hamper the movements of the hose 11 nor be exposed for interference with the person of the attendant.
As shown in Figures 2, 3 and 4 the air tube
27 extends within the nozzle 12 and preferably to one side thereof, terminating in an enlarged and flattened mouth 28 shown to best advantage in Figures 3 and 4. A characteristic of this mouth 28 is that it has a greater cross-section than the air tube 27 in order to make the closing of the liquid switch more sensitive. The mouth
28 is so spread that at its open end which is at or adjacent the open end of the nozzle 12 and within such nozzle it offers an arcuately elongated entrance for any liquid welling up or rising in the filling neck of the automobile tank into which the nozzle 12 has been thrust.
Thus the mouth 28 is arcuate to follow the contour of the internal curvature of the nozzle
12 and it is spread out so that radially it has a very narrow dimension, to eliminate any obstruction in the nozzle 12 to the free flow of liquid therethrough, and at the same time the mouth 28 is elongated and covers a substantial area so that its cross-section, particularly at its free edge, is materially greater than the cross-section of the air tube 27 into which it merges preferably in a fan wise manner as indicated in Figure 3.
In the operation of the device the parts are generally as shown in Figure 1 in normal operation with the electrolyte 24 in the left leg of the U-tube lying below the upper contact 22. Thus at this contact 22 the circuit 20, 21 is open. The valve 13 is thus released to the action of its spring 14. Such spring holds the valve 13 in the open position indicated so that normally no interference is had from the present device with the free flow of gasoline or other liquid in the conduit 10.
So soon as liquid rises to imminent overflow proportions in the filling neck of the automobile tank, such rising liquid will envelop the free end of the nozzle 12 and will therefore cover the mouth 28 and ascend therein in relatively great cross-sectional volume due to the spread nature of the mouth 28. Such enlarged body of liquid ascending in the nozzle 28 will force the entrapped air upwardly through the air tube 27 thereby pushing the electrolyte 24 around in the U-tube until such electrolyte bridges the contacts 22 and 23 and closes circuit 20, 21. With the consequent energizing of the solenoid coil 19 the core 18 will be axially projected to close the valve
13 and thus immediately cut off the supply of the liquid through the conduit 10. The sensitivity of the device is a characteristic of its operation in that the valve 13 is instantaneously closed with reference to the entrance of liquid into mouth 28 so that any rise of the liquid into the filling neck of the automobile tank will communicate its presence to the valve 13 before the liquid can sufficiently rise to overflow from such filling neck. The construction of the mouth 23 increases the sensitivity of operation in that the large volume of liquid accommodated in the large cross-section of the mouth 28 multiplies its rising
effect on the air in the narrower tube 21 to move the air through a relatively greater corresponding axial distance in the air tube 27 and consequently adequately at all times communicating suffl
S cient axial movement to the electrolyte 24 to effect closure of the switch 22, 23.
In view of the foregoing it will be appreciated that the device is extremely simple in operation, that it is sensitive and instantaneous in action,
10 that the valve 13, switch 22, 23 and electrolyte 24 are all susceptible of being enclosed out of sight in the casing of the standard pump at a remote point from the nozzle 12 and at a remote point from the gasoline in the open gasoline tank, so
15 that the device is adaptable to be approved by the underwriters.
As soon as the liquid recedes from out of the mouth 28, the pressure on the air in the air tube 27 will be released and the electrolyte 24
20 will be allowed to be restored to its initial position of equilibrium where such electrolyte is out of contact with the upper contact 22. The open leg 28 forms also a convenient point at which to replenish the U-tube with the elec
25 trolyte solution.
If the air tube 27 is enlarged or spread (28) such that the area of the opening of the spread portion is three times that of the open area of air tube 27, then the air will move three times
SO as fast through the air tube 27, as it will through the spread portion 28. The spread portion can of course be made to fit the inner contour of the nozzle 12. It is obvious that various changes and modi
35 fications may be made in the details of construction and design of the above specifically described embodiment of this invention without departing from the spirit thereof, such changes and modifications being restricted only by the
40 scope of the following claims. What is claimed is:
1. In combination with a conduit, a normally open valve therein controlling movement of liquid through said conduit, closing means for the
45 valve, a fluid-actuated control means for said closing means, a fluid tube to said control means, and a liquid receiving mouth on the tube of greater cross-section than the tube so constructed and arranged that liquid entering said mouth
50 will force fluid through the tube to actuate said control means.
2. A liquid cut-off device comprising a conduit for liquid, a valve therein, means to normally hold the valve open, electro-magnetic means for
55 closing the valve, a normally-open circuit for said electro-magnetic means, a switch controlling the closing of said circuit, and pneumatic means for shifting the switch to closed position comprising an air tube and an open liquid re
co ceiving mouth for the air tube, said mouth being of larger cross-section than the air tube to multiply the action of liquid entering the mouth on the column of air in the air tube.
3. In combination with the conduit, flexible C5 hose and nozzle of gasoline service station equipment, an air tube associated therewith having a liquid receiving mouth in the nozzle enlarged over the cross-section of the tube, so constructed and arranged that liquid rising in said mouth
70 will produce a proportionately greater movement of air in the air tube, a normally-open valve in the conduit, and means controlled by movement of air in said tube for causing the closing of said valve.
75 4. In combination with the conduit, flexible
hose and nozzle of gasoline service station equipment, an air tube associated therewith having a liquid receiving mouth in the nozzle positioned to receive liquid rising in the filling neck of an automobile gas tank, said mouth being arcuate, flattened in a radial sense and elongated in a circumferential direction, so constructed and arranged that liquid rising in said mouth will produce a proportionately greater rise in the column of air in said air tube, a normally-open valve in the conduit, and means controlled by movement of air in said tube for causing the closing of said valve.
5. In combination with the conduit, flexible hose and nozzle of gasoline service station equip-, ment, a valve in the conduit, yieldable means
biasing the valve to open position, an electromagnet, a movable core of the magnet carrying said valve, a circuit including said electromagnet, spaced contacts in said circuit, a source
5 of current supply impressed on said circuit, a U-tube having one leg open to atmosphere and carrying said contacts one vertically above another and extending through the wall of the leg, an electrolyte liquid in the tube up to a
]0 normal level below at least the upper contact, an air tube connected to the other leg of the U-tube, and a mouth on the air tube located at the nozzle and being of fan-shape curved to agree with the contour of the nozzle and flat
15 tened in the direction of radii of the nozzle.
DAVID N. FULTON.